cypress 0.1.0

use crate::parser::*;

/// A parser combinator that applies the inner parser `p` zero or more times,
/// collecting all successful parse results into a vector.
///
/// This combinator repeatedly applies the parser `p` until it fails,
/// and returns a vector of all successfully parsed values.
///
/// # Type Parameters
///
/// * `P` - The parser type to apply repeatedly.
pub struct PMany<P> {
    /// The inner parser to apply repeatedly.
    p: P,
}

/// Creates a new `PMany` parser combinator that applies parser `p` zero or more times.
///
/// # Arguments
///
/// * `p` - The parser to apply repeatedly.
///
/// # Returns
///
/// A `PMany` instance implementing `ParserCore` that collects multiple parse results
/// into a `Vec`.
pub fn pmany<P>(p: P) -> PMany<P> {
    PMany { p }
}

impl<'a, K, O, P> ParserCore<'a, K, Vec<O>> for PMany<P>
where
    K: PartialEq + Clone + 'a,
    O: 'a,
    P: Parser<'a, K, O>,
{
    /// Parses zero or more occurrences of the inner parser `p`.
    ///
    /// This method repeatedly attempts to parse the input using `p`, pushing
    /// each successful parse result into a vector. Parsing stops when `p` fails.
    ///
    /// # Arguments
    ///
    /// * `i` - The input to parse.
    ///
    /// # Returns
    ///
    /// Always returns `Ok(PSuccess)` with a vector of all parsed values (which
    /// may be empty) and the remaining input.
    fn parse(&self, i: PInput<'a, K>) -> Result<PSuccess<'a, K, Vec<O>>, PFail<'a, K>> {
        let mut vals: Vec<O> = vec![];
        let mut input = i;

        // Repeatedly parse input with `p` until it fails
        while let Ok(PSuccess { val, rest }) = self.p.parse(input.clone()) {
            vals.push(val);
            input = rest;
        }

        // Return all successfully parsed values and the remaining input
        Ok(PSuccess {
            val: vals,
            rest: input,
        })
    }
}

impl<'a, K, O, P> Parser<'a, K, Vec<O>> for PMany<P>
where
    K: PartialEq + Clone + 'a,
    O: 'a,
    P: Parser<'a, K, O>,
{
}